81625403028 has 24 divisors (see below), whose sum is σ = 205109987488. Its totient is φ = 25115508576.

The previous prime is 81625403011. The next prime is 81625403029. The reversal of 81625403028 is 82030452618.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81625403029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 261619726 + ... + 261620037.

Almost surely, 2^81625403028 is an apocalyptic number.

It is an amenable number.

81625403028 is an abundant number, since it is smaller than the sum of its proper divisors (123484584460).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81625403028 is a wasteful number, since it uses less digits than its factorization.

81625403028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 523239783 (or 523239781 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 39.

The spelling of 81625403028 in words is "eighty-one billion, six hundred twenty-five million, four hundred three thousand, twenty-eight".